How to save fuel - the ultimate guide

Drivers across Britain endured the steepest monthly rise in petrol prices for 18 years last month, RAC Fuel Watch found.

To combat May's price rises we have put together our ultimate guide on how to save fuel, and money, through more economical driving...

It is a fact that the faster you drive, the greater your fuel consumption.

Department for Transport figures state that you will use up to 9% more fuel driving at 70mph than you would at 60mph, and travelling at 80mph can use up to 25% more fuel than at 70mph.

Speed is arguably the most influential factor affecting fuel consumption, however, there are a number of other ways you can change your driving habits that will have a significant accumulated impact on the money you spend on fuel.

The ever-fluctuating cost of fuel (monitored by our very own RAC Fuel Watch team) is a constant source of frustration for motorists, so here we have provided some of our top fuel saving tips to help you stretch as many miles to the gallon as possible.

1. Less fuel equals more fuel

If you tend to be an urban driver, only have half a tank of fuel – less weight will help fuel economy.

2. Plan your route

Consider making one round trip rather than several short trips. Once the engine is warm it will operate at its most efficient whereas several cold starts will increase fuel consumption even though the total mileage could be the same - visit the RAC Route Planner to help plan your journey in a more fuel efficient way.

3. Make sure you maintain your vehicle

Regular maintenance and servicing improves the efficiency of your vehicle. And therefore can improve your fuel consumption below is a short video on important maintenance checks you should regularly carry out.

4. Slowest speed, highest gear

The secret to achieving a high mpg figure is driving at the lowest speed you can, in the highest possible gear.

This optimum fuel economy speed will be different for every car, but when the RAC completed its record road trip in the Audi A6 ultra, that particular car’s optimum fuel economy speed was 52mph in seventh gear on the flat.

While there is an ideal speed, road conditions and gradients don’t often allow you to do that speed so you have to improvise and learn to adjust your driving according to the road ahead, this technique is called hypermiling, which we discuss in the next section.

Generally speaking, the optimum driving speed for fuel economy is 55/56mph, which is what car manufacturers typically use to quote fuel consumption figures. However, as well as differing dependent on your vehicle, fuel economy is also dependent on a number of different factors such as tyre pressure, excess weight in the boot, presence of roof racks, driving style, etc covered in this guide.

5. Does cruise control use more fuel?

Actually, yes, if you were to use it all the time. Cruise control only aids fuel economy when driving on a constant flat surface, hence why it is usually good for motorway driving.

One of the keys to saving fuel is driving at a constant speed, cruise control can do this effectively on flat surfaces, making your driving is as fuel efficient as possible by negating unnecessary acceleration.

However, if you were to use your cruise control regularly, not on flat roads, you would encounter problems that would increase your fuel consumption.

This is because your cruise control would be slower to react to gradient changes, meaning when reaching the brow of a hill - at which point you would normally take your foot off the accelerator to maintain more of a constant speed when descending - your cruise control will keep the power on for a little longer, unable to see the gradient change in front.

Driving in this way regularly would accumulate to an increased fuel consumption.

6. Maintain momentum

In line from the above point keeping the car moving is essential to fuel economy. Obviously this depends on traffic conditions and what’s happening on the road ahead, but slowing down and having to accelerate again naturally uses more fuel.

7. Gentle right foot

Having a light right foot and ensuring all acceleration is gentle is definitely important, of course you will always have to accelerate a number of times on a journey but that doesn't mean you have to pull away like you're on the starting line of Silverstone.

Conserving momentum and using it to your advantage is as important for setting good fuel consumption figures as simply not going very fast. You really don’t do very well if you only cut the speed.

3. Look well ahead

If you look well ahead, you’ll be able to spot that truck in the distance. You’ll see the traffic lights on red meaning you can ease back on the throttle and glide up to the obstruction usually as it clears.

By keeping your eyes focused on the distance, you can make the gentle adjustments early to ensure your flow is unimpeded. At times, when the traffic lights turn to green just as you drive up to them, your passenger will think wizardry is at work…

4. Remember the revs

The faster an engine spins, the more fuel it uses. So keep the revs low by changing up early.

You’ll soon see the fuel computer start to reward you. Just don’t let the engine labour, as you’ll quickly bog down and begin losing speed. Try to keep the engine speed in the ideal eco spot.

5. Be patient

How satisfying it is to come up behind that person who overtook you half an hour earlier?

We did just that – indeed, we’d actually forgotten the impatient sports car driver had roared past us until we came back across him later on at a busy intersection.

More haste doesn’t necessarily deliver more speed. If the roads are busy, trying to tear past everyone is unlikely to save you much time, if any.

6. Be clever with hills

Driving up hills destroys fuel economy. It may feel good to accelerate up them, but this is disastrous for your mpg.

Instead, try to drive them cleverly. If you spot a clear hill ahead, accelerate a little before you reach it, then ease off as you drive up. The extra momentum should be enough to minimise additional consumption.

7. Embrace the motorway

The most fuel-efficient roads in the country are not quiet extra-urban dual carriageways or 20mph city streets. They are motorways. This is where you can leave the car in top gear and gently cruise along, using minimal fuel.

You’re probably going faster from point-to-point than if you went cross-country, too. Shortest is not always greenest.

Rebecca Jackson’s advice

“To set any kind of fuel efficiency world record you have to be looking ahead as much as possible to pre-empt oncoming hazards. This is a good general driving habit but it was absolutely crucial for us.

"It’s all about keeping moving and not losing momentum. Accelerating from being stopped is very costly in fuel consumption terms and so is going up any steep incline.

“We tried not to use the brakes as much by easing off the throttle to reduce speed. If you can keep moving slowly rather than stopping in traffic that’s good, but you do have to be conscious of not being a pain to other drivers by leaving too much of a gap behind the car in front.

“You need to listen to the engine to make sure you don’t use excessive revs but you need to use enough, so it’s a fine balance as you don’t want the car to be labouring too much either.”

Andrew Frankel’s advice

“If you are coming up to a roundabout you need to know whether you will be able to get through without slowing down too much by adjusting your speed very carefully before you enter.

“And, if you have a hill coming up you need to judge not just the gradient, but its likely duration too. If you can see it’s just a short rise it’s better to coast up, lose the speed and stay in gear rather than change down early. Each hill is therefore different and there is of course an element of guesswork.”

** 10% of all customers buying Car Insurance Plus with us from 1st January 2018 to 30th June 2018 paid less than £165. Based on comprehensive Car Insurance Plus, purchased direct, excluding any additional products and upgrades, with payment on an annual basis. Your premium will depend on your circumstances and the level of cover you choose.

*New, Vehicle based Roadside only on a monthly auto renewing contract

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